body,html{
  margin: 0;
  padding: 0;
}

#main {
  margin: 50px auto;
  width: 260px;
}

#calc {
  margin-left: 52px;
  width: 60px;
}
span {
  color:red;
  margin-left:  5px;
}

input {
  margin: 5px 0;
}
#width-validate,height-validate {
  color: red;
  margin-left: 52px;
}
